Optoelectronic device and adaptive illumination system using the same

ABSTRACT

An automotive headlight is disclosed including: an optical unit including a plurality of optical elements, each optical element having a different central direction; a segmented light-emitting diode (LED) chip including a plurality of LEDs that are separated by trenches formed on the segmented LED chip and arranged in a plurality of sections, each section being aligned with a different respective optical element, and each section including at least one first LED and at least one second LED; and a controller configured to: apply a forward bias to each of the first LEDs, apply a reverse bias to each of the second LEDs, and change a brightness of the first LEDs in any section based on a signal generated by the second LED in that section.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/948,642 filed Apr. 9, 2018, and a continuation of Ser. No.15/699,573, filed Sep. 8, 2017, which is/are incorporated by referenceas if fully set forth.

FIELD OF INVENTION

The present disclosure relates to light emitting devices in general, andmore particularly, to an optoelectronic device and adaptive illuminationsystem using the same.

BACKGROUND

Light emitting diodes (“LEDs”) are commonly used as light sources invarious applications. LEDs are more energy-efficient than traditionallight sources, providing much higher energy conversion efficiency thanincandescent lamps and fluorescent light, for example. Furthermore, LEDsradiate less heat into illuminated regions and afford a greater breadthof control over brightness, emission color and spectrum than traditionallight sources. These characteristics make LEDs an excellent choice forvarious lighting applications ranging from indoor illumination toautomotive lighting.

Accordingly, the need exists for improved solid-state lighting designsthat leverage the advantages of LEDs over traditional light sources, toachieve greater robustness and increased functionality.

SUMMARY

According to aspects of the disclosure, an automotive headlight isdisclosed including; an optical unit including a plurality of opticalelements, each optical element having a different central direction; asegmented light-emitting diode (LED) chip including a plurality of LEDsthat are separated by trenches formed on the segmented LED chip andarranged in a plurality of sections, each section being aligned with adifferent respective optical element, and each section including atleast one first LED and at least one second LED; and a controllerconfigured to; apply a forward bias to each of the first LEDs, apply areverse bias to each of the second LEDs, and change a brightness of thefirst LEDs in any section based on a signal generated by the second LEDin that section.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described below are for illustration purposes only. Thedrawings are not intended to limit the scope of 1he present disclosure.Like reference diameters shown in the figures designate the same partsin the various embodiments.

FIG. 1 is a schematic top-down view of an example of a segmented lightemitting diode (LED) chip, according to aspects of the disclosure;

FIG. 2 is a schematic side view of an example of the segmented LED chipof FIG. 1, according to aspects of the disclosure;

FIG. 3A is a diagram illustrating an example of an operational patternthat can be imparted on a segmented LED chip, according to aspects ofthe disclosure;

FIG. 3B is a diagram illustrating another example of an operationalpattern that can be imparted on a segmented LED chip, according toaspects of the disclosure;

FIG. 3C is a diagram illustrating yet another example of an operationalpattern that can be imparted on a segmented LED chip, according toaspects of the disclosure;

FIG. 4 is a schematic top-down view of another example of a segmentedLED chip, according to aspects of the disclosure;

FIG. 5 is a schematic top-down view of another example of a segmentedLED chip, according to aspects of the disclosure;

FIG. 6 is a schematic diagram of an example of an adaptive lightingsystem, according to aspects of the disclosure;

FIG. 7 is a schematic diagram of another example of an adaptive lightingsystem, according to aspects of the disclosure;

FIG. 8 is a diagram illustrating an example of the operation of anadaptive automotive lighting system that uses a segmented LED chip,according to aspects of the disclosure;

FIG. 9 is a diagram illustrating an example of an adaptive action thatcould be taken by the adaptive automotive lighting system of FIG. 8,according to aspects of the disclosure;

FIG. 10A is a diagram illustrating an example of another adaptive actionthat could be taken by the adaptive automotive lighting system of FIG.8, according to aspects of the disclosure;

FIG. 10B is a diagram illustrating an example of another adaptive actionthat could be taken by the adaptive automotive lighting system of FIG.8, according to aspects of the disclosure:

FIG. 11A is a schematic exploded view of a headlight that can be used inthe adaptive automotive lighting system of FIG. 8, according to aspectsof the disclosure;

FIG. 11B is a schematic side view of the headlight of FIG. 11A,according to aspects of the disclosure;

FIG. 12 is a diagram illustrating the operation of the headlight of FIG.11A, according to aspects of the disclosure;

FIG. 13 is flowchart of an example of a process for avoiding crosstalkbetween emitter LEDs and reflector LEDs in a segmented LED chip,according to aspects of the disclosure;

FIG. 14A is schematic top-down view of an example of a segmented LEDchip that is optimized to avoid crosstalk between emitter LEDs anddetector LEDs situated on the chip's die, according to aspects of thedisclosure;

FIG. 14B is schematic side view of the segmented LED chip of FIG. 14A,according to aspects of the disclosure;

FIG. 15 is a flowchart of an example of a process for operating an LEDmatrix, according to aspects of the disclosure; and

FIG. 16 is a flowchart of an example of a process for operating a groupof LEDs in an LED matrix, according to aspects of the disclosure;

FIG. 17 is a flowchart of an example of a process for operating an LEDmatrix, according to aspects of the disclosure.

DETAILED DESCRIPTION

According to aspects of the disclosure, a segmented light-emitting diode(LED) chip is disclosed that includes a plurality of LEDs. Each LED onthe segmented LED chip is provided with a pair of contacts which permitsthe LED to be biased separately from the rest. As a result, some of theLEDs in the segmented LED chip can be used as detectors for detectingambient light while others are can be used as emitters. Any given LED inthe segmented LED chip may be used as an emitter when forward bias, isapplied to that LED. Similarly, any LED in the segmented LED chip may beused as a detector when a reverse bias is applied to that LED.

According to aspects of the disclosure, some of the LEDs in thesegmented LED chip may be optimized for use as detectors. For example,any of the optimized LEDs may be provided with a filter structure fornarrowing its absorption band. As another example, any of the optimizedLEDs may be further doped by ion implantation for example to shiftand/or expand that LEDs absorption band. As yet another example, any ofthe optimized LEDs may be both provided with a filter structure andadditionally doped to fine-tune that LED's absorption band.

According to aspects of the disclosure, the segmented LED chip can beused to build an improved adaptive lighting system. Traditional adaptivelighting systems include light emitters and light detectors that arelocated on separate chips. However, because the segmented LED chipincludes both light emitters and light detectors on the same die, thenumber of parts that need to be included in the improved adaptivelighting system is reduced along with the system's sensor footprint.

According to aspects of the disclosure, the segmented LED chip maypermit emitters and light detectors to share the same optics. Becauseemitters and light detectors are situated in close proximity to oneanother on the chip's die, they cart both fit under the same lens (oranother type of optical unit), without the need for optical alignment.As can be readily appreciated, fitting the emitters and detectors underthe same lens eliminates the need for periodic optical alignments thatcould be necessary if the emitters and light detectors were to useseparate lenses.

According to aspects of the disclosure, the segmented LED chip maypermit fine illumination control not found in traditional lightingsystems. Because emitters and light detectors are situated in closeproximity to one another on the chip's die, different emitter-detectorpairs can fit under different lenses in a lens array. Each lens in thearray may be configured to guide light emitted from its respectiveemitter in a different central direction. Additionally, each lens may beconfigured to pass through, to its respective light detector, light thatis incident on the lens from the lens's respective central direction.Thus, each lens's respective light detector may be effectivelyconfigured to measure ambient lighting conditions that are predominantlyassociated with the lens's respective emitter. This in turn can permitan emitter LED that is directed towards an area that is over-illuminatedto be dimmed without changing the brightness of other LEDs in thesegmented LED chip that are oriented towards areas that are notover-illuminated.

According to aspects of the disclosure, an apparatus is disclosedcomprising; a segmented light-emitting diode (LED) chip including aplurality of LEDs that are separated by trenches formed on the segmentedLED chip, each LED having a respective emission band and a respectiveabsorption band, wherein the plurality of LEDs includes one or morefirst LEDs and one or more second LEDs, and at least one of the secondLEDs is configured to have a different absorption band than any of thefirst LEDs as a result of processing performed on the segmented LED chipafter the trenches are formed.

According to aspects of the disclosure, an apparatus is disclosedcomprising: a segmented light-emitting diode (LED) chip including aplurality of LEDs that are separated by trenches formed on the segmentedLED chip, and a controller configured to: apply a forward bias to afirst LED and a second LED in the segmented LED chip; and change abrightness of each of the first LED and the second LED by differentamounts, wherein the brightness of the first LED is changed based on afirst signal generated by a reverse-biased LED in the segmented LED chipand the brightness of the second LED is changed based on a second signalthat is generated concurrently with the first signal by anotherreverse-biased LED in the segmented LED chip.

According to aspects of the disclosure, an apparatus is disclosedcomprising: a segmented light-emitting diode (LED) chip including aplurality of LEDs that are separated by trenches formed on the segmentedLED chip, and a controller configured to: apply a forward bias to one ormore first LEDs in the plurality; apply a reverse bias to one or moresecond LEDs in the plurality; and change a brightness of a given firstLED based on a signal generated by one or more given second LEDs thatare co-located with the given first LED.

Examples of different adaptive lighting systems will be described morefully hereinafter with reference to the accompanying drawings. Theseexamples are not mutually exclusive, and features found in one examplecan be combined with features found in one or more other examples toachieve additional implementations. Accordingly, it will be understoodthat the examples shown in the accompanying drawings are provided forillustrative purposes only and they are not intended to limit thedisclosure in any way. Like numbers refer to like elements throughout.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, these elements should notbe limited by these terms. These terms are only used to distinguish oneelement from another. For example, a first element could be termed asecond element, and, similarly, a second element could be termed firstelement, without departing from the scope of the present invention. Asused herein, the term “and/or” includes any and all combinations of oneor more of the associated listed items.

It will be understood that when an element such as a layer, region orsubstrate is referred to as being “on” or extending “onto” anotherelement, it can be directly on or extend directly onto the other elementor intervening elements may also be present. In contrast, when anelement is referred to as being “directly on” or extending “directlyonto” another element, there are no intervening elements present. Itwill also be understood that when an element is referred to as being“connected.” or “coupled” to another element, it can be directlyconnected or coupled to the other element or intervening elements may bepresent. In contrast, when an element is referred to as being “directlyconnected” or “directly coupled” to another element, there are nointervening elements present. It will be understood that these terms areintended to encompass different orientations of the element in additionto any orientation depicted in the figures.

Relative terms such as “below” or “above” or “upper” or “lower” or“horizontal” or “vertical” may be used herein to describe a relationshipof one element, layer or region to another element, layer or region asillustrated in the figures. It will be understood that these terms areintended to encompass different orientations of the device in additionto the orientation depicted in the figures.

FIGS. 1 and 2 depict an example of a segmented LED chip 100, accordingto aspects of the disclosure. Specifically, FIG. 1 is a top-down view ofthe segmented LED chip 100 and FIG. 2 is side view of the segmented LEDchip 100. The segmented LED chip 100 includes a single LED die that isdivided into multiple segments, each of which is configured to operateseparately from the rest. More particularly, in the present example, thesegmented LED chip 100 includes a plurality of LEDs 110 that areseparated by trenches 120 formed on the chip's die. Each of the LEDs 110in the segmented LED chip 100 is provided with a respective pair ofcontacts 130 that permit that LED to be biased separately from the rest.

In some implementations, the segmented LED chip 100 may be of similar oridentical size to a standard LED, and each LED 110 (e.g., a segment) canbe smaller than the typical LED. For example, a standard 1 mm×1 mm LEDchip could be made up of 5×5 LEDs (or segment) of 200 um×200 um each.The size depends on the separation between the segments (e.g., LEDs),which is dictated by the manufacturing capabilities. According to thepresent example, the LEDs 110 are electrically isolated from oneanother, the example by dry etching the die of the segmented LED chip100 down to an insulating substrate or submount to sever any electricalconnection between the LEDs 110. Contacts would be deposited on each LED110 separately in a well-known fashion.

Because the LEDs are capable of being biased separately, the segmentedLED chip 100 can be operated as an emitter and detector at the same timeby forward-biasing some of the LEDs 110 while reverse-biasing others. Asis well-known in the art, when a forward bias is applied to an LED, thatLED emits light and is said to operate as an emitter (or in emittermode) under the nomenclature of the present specification. Similarly,when a reverse bias is applied to a given LED that LED operates as aphotodetector and is said to operate as a detector (or in detector mode)under the nomenclature of the present specification. Furthermore,because each of the LEDs 110 in the segmented LED chip 100 can be biasedindependently, the location, as well as the relative numbers, of theemitters and detectors in the chip can be set selectively by any controlcircuit that drives the segmented LED chip 100. As is further discussedbelow, a given configuration of emitters and detectors in a segmentedLED chip can be referred to as an “operational pattern” that is impartedon that segmented LED chip.

FIGS. 3A, 3B, and 3C illustrate examples of different operationalpatterns that can be imparted on a segmented LED chip according toaspects of the disclosure. More particularly, FIG. 3A illustrates anexample of a segmented LED chip 300 a that is configured to operate inaccordance with a first operational pattern. As illustrated in thispattern, LEDs 312 a are reverse-biased and configured to operate asdetectors, while LEDs 314 a are forward-biased and configured to operateas emitters. FIG. 3B illustrates an example of a segmented LED chip 300b that is configured to operate in accordance with a second operationalpattern. As illustrated, according to the second operational pattern,LEDs 312 b are reverse-biased and configured to operate as detectors,while LEDs 314 b are forward-biased and configured to operate asemitters. FIG. 3C illustrates an example of a segmented LED chip 300 cthat is configured to operate in accordance with a third operationalpattern. As illustrated, according to the third operational pattern,LEDs 312 c are reverse-biased and configured to operate as detectors,while LEDs 314 c are forward-biased and configured to operate asemitters.

In some aspects, the number of LEDs that are operated as detectors canvary depending on the amount of sensitivity needed. If greatersensitivity is needed, more LEDs in a given segmented LED chip can beoperated as detectors. By contrast, if a reduced sensitivity is needed,fewer of the LEDs in the given segmented LED chip can be used asdetectors. Additionally or alternatively, in some implementations, allLEDs in a segmented LED chip can be configured to operate as emitters(e.g., put in forward bias). Additionally or alternatively, in someimplementations, all LEDs in a segmented LED chip can be configured tooperate as detectors (e.g., biased in the reverse direction).

In some implementations, the LEDs on a segmented LED chip can beconfigured to provide transient voltage suppression (TVS). In instancesin which it is desirable to operate all LEDs in a segmented LED chip asemitters, one LED may nevertheless be kept in the opposite polarity(e.g., biased in the reverse direction) to provide TVS. In instances inwhich it is desirable to operate all LEDs in a segmented LED chip asdetectors, one LED may nevertheless be kept in the opposite polarity(e.g., biased in the forward direction) to provide TVS.

In some aspects, some of the LEDs in a segmented LED chip can beoptimized to function as detectors. FIG. 4 is a mp-down view of asegmented LED chip 400 which includes LEDs 410 and 420 separated bytrenches 430 formed on the chip's die. Each of LEDs 410 and 420 has arespective absorption band and a respective emission band. However, theabsorption band of any of the LEDs 420 is different from the absorptionband of each of the LEDs 410. For example, any of the LEDs 420 can havean absorption band that is wider than the absorption band of each of theLEDs 410. As another example, any of the LEDs 420 may have an absorptionband that is shifted with respect to the absorption band of any of theLEDs 410. In some aspects, the difference between the absorption bandsof the LEDs 410 and 420 may be the result of fine-tuning the LEDs 420 tofit a particular application, such as detecting light emitted by halogenlight sources, which the LEDs 410 may not be able to detect well whenused as detectors.

Any of the LEDs 420 may start as a structure that is identical to any ofthe LEDs 410, which is further modified by means of ion implantation forexample after the trenches 430 are formed to produce the LED 420. As aresult of the ion implantation, additional atoms and/or defects (e.g.,vacancies, interstitials, substitutionals, etc.) may be present in thecrystal lattices of the LEDs 420 that are not found in the crystallattices of the LEDs 410. Those additional atoms and/or defects createdeep level traps within the LED active region bandgap, and these deeplevel traps act as lower energy (i.e., longer wavelength) absorptioncenters which ultimately result in the LEDs 420 having a differentabsorption band than the LEDs 410. In some implementations, any of theLEDs 420 may include a greater concentration of atoms of a givenimplanted element (e.g., iron, phosphorus, arsenic, antimony, bismuth)or resulting point defect (e.g., vacancies, interstitials, etc.) thaneach of the LEDs 410. For example, the atoms of the given element may bepresent in lower concentrations in the LEDs 410 or not present at all.Additionally or alternatively, in some implementations, any of the LEDs420 may include a greater concentration of point defects than each ofthe LEDs 410.

Although in the present example, all LEDS 420 have the same adsorptionband, in some implementations at least some of the LEDs 420 may havedifferent absorption bands. For example, the segmented LED chip 400 mayinclude a first LED 420 that is optimized to detect light emitted fromhalogen headlights, a second LED 420 that is optimized to detect lightemitted from xenon headlights, and a third LED 420 that is optimized todetect light from incandescent headlights. In some aspects, each of thefirst, second, and third LEDs 420 (or at least two of them) may be dopedwith a different element and/or in different amounts to achieve thevariation in absorption bands.

In some implementations, the absorption band of the second LEDs can bealtered by changing the magnitude of reverse bias applied while servingas a detector. In III-nitride LEDs for example, an increase in reversebias magnitude first shifts the absorption band to shorter wavelengthsas quantum well bands flatten as applied bias counters thepolarization-induced electric fields within the active region. As thereverse bias magnitude continues to increase, the absorption band shiftsto longer wavelengths.

FIG. 5 depicts another example of a segmented LED chip 500, whichincludes LEDs that are optimized for use as detectors, according toaspects of the disclosure, The segmented LED chip 500 includes LEDs 510and LEDs 520 that are separated by trenches 530 formed on the chip'sdie. Each of the LEDs 520 is provided with a filter structure formed onone or more of its respective light emitting surface(s). As a result ofbeing provided with a filter structure, any of the LEDs 520 may have anarrower absorption band than each of the LEDs 510. In some aspects, thedifference between the absorption bands of the LEDs 510 and 520 may bethe result of fine-tuning the LEDs 520 to fit a particular purpose.

In some implementations, the respective filter structures of the LEDs520 may be formed after the trenches of the segmented LED chip 500 havebeen etched. Each of the LEDs 520 may start as a base structure (e.g.,an LED) that is substantially identical to the LEDs 510, which isfurther processed to include a respective filter structure on one ormore of its surfaces. The respective filter structures of the LEDs 520may be deposited using any suitable type of technique, such as plasmaenhanced chemical vapor deposition, atomic layer deposition orsputtering for example. The respective filter structures may be formedof any suitable type of material such as dielectric layers or stacks ofdielectric layers for forming distributed Bragg reflectors (DBRs) thatcreate high reflectivity of certain wavelengths of light not desired toimpinge on the LED, for example. The present disclosure is not limitedto any particular type of process for depositing the filter structureand/or composition.

As noted above, each of the LEDs 520 may be formed by covering a basestructure (e.g., an LED) that is substantially identical to one of theLEDs 510 with a respective filter structure. In some aspects, the filterstructure of a given LED 520 may be configured to have a transmittanceband that only partially overlaps with the absorption band of the givenLED's 520 base structure. For example., the filter structure of thegiven LED 520 may have a transmittance band having a respective lowerbound and a respective upper bound. Similarly, the base structure of thegiven LED 520 (or any of the LEDs 510) may have an absorption bandhaving a respective lower bound and a respective upper bound. It someaspects, the lower bound of the transmittance band of the filterstructure may be greater than the lower bound of the absorption band ofthe base structure (or any of the LEDs 510). Additionally oralternatively, the upper bound of the transmittance band of the filterstructure may be lower than the upper bound of the absorption band ofthe base structure of the given LED 520 (or any of the LEDs 510).

FIG. 6 is a schematic diagram of an example of an adaptive lightingsystem 600, according to aspects of the disclosure. The adaptivelighting system 600 includes a segmented LED chip 610 and a controller620, as shown. The controller 620 includes driver circuits 622 a-d and acontrol circuit 624.

Each of the driver circuits 622 a-d is coupled to a different group ofLEDs on the segmented LED chip 610. For example, the driver circuit 622a is coupled to LEDs 612 a and 614 a, which are part of group A. Thedriver circuit 622 b is coupled to LEDs 612 b and 614 b, which are partof group B. The driver circuit 622 c is coupled to LEDs 612 c and 614 c,which are part of group C. The driver circuit 622 d is coupled to LEDs612 d and 614 d which are part of group D. According to the presentexample, each of LEDs 612 a-d is configured to operate as an emitter byapplying a forward bias to it. Furthermore, according to the presentexample, each of LEDs 614 a-d is configured to operate as a detector byapplying a reverse bias to it. Thus, each of the driver circuits 622 a-dis connected to an emitter LED and a detector LED. Although in thepresent example each of groups A-D includes only one emitter and onedetector, alternative implementations are possible in which any ofgroups A-D includes multiple emitters and/or multiple detectors. Forexample, any of groups A-D may include any number of emitters. (e.g., 1,5, 20, 30, etc.). Similarly, any of groups A-D may include any number ofdetectors (e.g., 1, 5, 20, 30, etc.) For instance, in someimplantations, any of groups A-D may include one detector and fiveemitters. Thus, in some implementations, the emitters and detectors neednot be matched in pairs.

According to aspects of the disclosure, driver circuit 622 a may beconfigured change the brightness of the LED 612 a based on a signalgenerated by the LED 614 b. In some implementations, changing thebrightness of the LED 612 a may include increasing the brightness of theLED 612 a, decreasing the brightness of the LED 612 a (e.g., dimming theLED 612 a), turning on the LED 612 a, and turning off the LED 612 a.Alternatively, in some implementations, changing the brightness of theLED 612 a may include only increasing the brightness of the LED 612 aand decreasing the brightness of the LED 612 a (e.g., dimming the LED612 a). According to the present example, the LED 612 a may beconsidered switched off if it remains turned off for a period that islonger than the off-period of a pulse-width modulation (PWM) wave usedto drive the LED 612 a when the LED 612 a is energized. For example, theLED 612 a may be considered to be switched off if it is not suppliedwith power for a duration that is longer than the sum of the on-periodand the off-period of the PWM wave. As another example, the LED 612 amay be considered to be switched off if it is not supplied with powerfor 1 second or longer. In some implementations, increasing thebrightness of the LED 612 a may include increasing the current suppliedto the LED 612 a. Additionally or alternatively, in someimplementations, decreasing the brightness of the LED 612 a may includedecreasing the current supplied to the LED 612 a without completelyshutting it off. Additionally or alternatively, turning on the LED 612 amay include starting to supply current to the LED 612 a when the LED 612a is not energized.

In some implementations, the driver circuit 622 a may change thebrightness of the LED 612 a in accordance with the amount of light thatis incident on the LEDs in group A. For example, when the signalgenerated by the LED 614 a indicates that a large amount of light isincident on the LEDs in group A, the driver circuit 622 a may decreasethe brightness of the LED 612 a. Alternatively, when the signalgenerated by the LED 614 a indicates that a low amount of light isincident on the LEDs in group A, the driver circuit 622 a may increasethe brightness of the LED 612 a. Thus, according to the present example,the driver circuit 622 a implements an adaptive lighting feature that islocal to a group of LEDs and/or a portion of the segmented LED chip 610.

In some implementations, the driver circuit 622 a may decrease thebrightness of the LED 612 a when the signal generated by the LED 614 acrosses a first threshold. Additionally or alternatively, the drivercircuit 622 a may increase the brightness of the LED 612 a when thesignal generated by the LED 614 a crosses a second threshold.Additionally or alternatively, the amount by which the brightness of theLED 612 a is decreased or increased may be proportional to a change inthe value of the signal generated by the LED 614 a. Thus, in someimplementations, the brightness of the LED 612 a can be adjustedcontinuously, rather than in discrete steps.

In some implementations, the LED 614 a may be continuously operated as adetector. Alternatively, in some implementations, the LED 614 a may beoperated as both a detector and an emitter For example, the bias of theLED 614 a may be periodically switched by the driver circuit 622 a fromforward to reverse to take a reading, and then returned to forward.(E.g., see FIG. 13). The switching of the bias of the LED 614 a mayoccur very rapidly (e.g., <10 ns) to allow for light collection. In someimplementations, the bias of the LED 614 a may be switched at a veryhigh frequency, so that the changes in the state of the LED 614 a areimperceptible to the human eye. According to the present example, theLEDs 614 b-d may be operated in a similar manner by their respectivedriver circuits.

Each of the driver circuits 612 b-c may operate in a manner similar tothe driver circuit 622 a. More particularly, the driver circuit 622 bmay be any suitable type of circuit that is configured to change thebrightness of the LED 612 b based on a signal that is at generated bythe LED 614 b. The driver circuit 622 c may be any suitable type ofcircuit that is configured to change the brightness of the LED 612 cbased on a signal that is generated by the LED 614 c. And the drivercircuit 622 d may be any suitable type of circuit that is configured tochange the brightness of the LED 612 d based on a signal that isgenerated by the LED 614 d.

The control circuit 624 may include a field-programmable gate array(FPGA), an application-specific integrated circuit (ASIC), a processor,a memory, and/or any other suitable type of circuitry that is configuredto change the state of any of driver circuits 612 a-d. For example,changing the state of a given driver circuit may include causing thegiven driver circuit to increase or decrease the bias that is applied toa particular detector LED. As another example, changing the state of agiven driver circuit may include causing the driver circuit to increaseor decrease the amount of current supplied to a particular emitter LED.Thus, in some implementations, the control circuit 624 may be configuredto set a relationship between the signal produced by a given detectorLED(s) and the light output of associated emitter LED(s) that issubsequently enforced by a driver circuit that is connected to the givendetector LED(s) and their associated emitter LED(s).

In some implementations, the control circuit 624 may be omitted from thecontroller 620. In such instances, each of LED groups A-D may becontrolled by a separate driver circuit, completely independently of therest.

In the present example, the controller 620 is configured to control anLED matrix including a single segmented LED chip. However, in someimplementations, the controller may be configured to control an LEDmatrix that includes a plurality of segmented LED chips and/or one ormore non-segmented LED chips. For example, the controller 620 may beconfigured to control an LED matrix including four segmented LED chips,such that each of the driver circuits 622 a-d is connected to adifferent one of the segmented LED chips.

In the present example the LEDs in groups A-D are hardwired to differentdriver circuits. However, in some implementations, the controller 620may be provided with a switching fabric that enables the control circuit624 to selectively assign control over the LEDs in the segmented LEDchip 610 to any of the driver circuits. For example, the switchingfabric may enable the control circuit 624 to connect all LEDs in thesegmented LED chip 610 to a particular driver circuit. Alternatively,the switching fabric may enable the control circuit 624 to connect halfof the LEDs in the segmented LED chip 610 to one driver circuit, whileconnecting the other half to another driver circuit. Stated succinctly,the switching fabric may permit the control circuit 624 to dynamicallygroup the LEDs in the segmented LED chip 610 into any number of groups,and assign each group to a different driver circuit.

FIG. 7 is a diagram of an example of an adaptive lighting system 700,according to aspects of the disclosure. The adaptive lighting system 700includes a segmented LED chip 710 coupled to a controller 720. Thecontroller 720 includes a processor 722, a memory 724, and a driver 726.The processor 722 may include any suitable type of processor, such asone or more of an application-specific integrated processor (ASIC), afield-programmable gate array (FPGA), a general-purpose processor (e.g.,an ARM-based processor, an x86-base d processor, a MIPS processor,etc.). The memory 724 may include any suitable type of volatile andnon-volatile memory, such as DRAM, EEPROM, flash memory, a solid-statedrive (SSD), and a hard drive. The driver 726 may include any suitabletype of electronic circuit configured to bias and/or supply current toany of the LEDs in the segmented LED chip 710.

In some implementations, the controller 720 may configure some of theLEDs in the segmented LED chip 710 to operate as emitters by applying aforward bias to those LEDs. Furthermore, the controller 720 mayconfigure others of the LEDs in the segmented LED chip 710 to operate asdetectors, by reverse-biasing those LEDs. Afterwards, the controller 720may change the brightness of any of the emitter LEDs based on signal(s)generated by one or more the detector LEDs, as discussed with respect toFIGS. 15-17 below.

In some implementations, the controller 720 may be configured to addresseach of the LEDs in the segmented LED chip 710 individually. Forexample, the controller 720 may be configured to change the magnitudeand/or polarity of the bias of any LED in the segmented LED chip 710independently from the rest. As another example, the controller 720 maybe configured to increase or decrease the current supplied to any LED inthe segmented LED chip 710 without changing the supply of current to anyof the other LEDs in the segmented LED chip 710. As another example, thecontroller 720 may be configured to detect a signal that is generated byone of the LEDs in the segmented LED chip 710. Although in the presentexample the controller 720 is used to control an LED matrix consistingof a single segmented LED chip, alternative implementations are possiblein which the controller 720 is configured to control any suitable typeof LED matrix, such as a matrix including multiple segmented LED chips,and/or a matrix including one or more non-segmented LED chips.

FIG. 8 is a diagram illustrating an example of the operation of anadaptive automotive lighting system that uses a segmented LED chip,according to aspects of the disclosure. In this example, vehicles 810and 830 are travelling in opposite directions on a road 800. Each of theheadlights of the vehicles 810 and 830 includes a segmented LED chip (oranother type of LED matrix) that is driven by a controller configured totake an adaptive action when oncoming traffic is encountered.

According to the present example, the vehicle 810 includes headlights812 and 814 which are turned on to illuminate a space 322 and a space824, respectively. The space 822 may include a corresponding section ofthe road 800 ahead of the vehicle 810, as well as the space above it.Similarly, the space 824 may include another corresponding section ofthe road 800 ahead of the vehicle 810, as well as the space above it.The vehicle 830 includes headlights 832 and 834 which are turned on toilluminate a space 842 and a space 844, respectively. The space 842includes a corresponding section of the road 800 ahead of the vehicle830, as well as the space above it. Similarly, the space 844 may includeanother corresponding section of the road 800 ahead of the vehicle 830,as well as the space above it.

In some implementations, the headlights 812 and 814 may be operated bythe same controller that is configured to take various adaptive actionson behalf of the vehicle 810, as discussed further below. Additionallyor alternatively, the headlights 812 arid 814 may be operated bydifferent respective controllers. Accordingly, it will be understoodthat the present disclosure is not limited to any specific systemtopology of the adaptive lighting systems of vehicles 810 and 830.

FIG. 9 is a diagram illustrating an example of an adaptive action thatcould be taken by the adaptive automotive lighting system of FIG. 8 whenoncoming traffic is encountered, according to aspects of the disclosure.More particularly, when vehicle 830 enters the space 822, the headlight812 detects light emitted from the headlight 832 of the vehicle 830 byusing one or more detector LEDs in the headlight's segmented LED chip.In response, the headlights 812 and 814 are turned off to avoid blindingthe driver of the vehicle 830. When the vehicles 810 and 830 pass eachother, the light emitted from the headlight 834 no longer illuminatesthe detector LEDs in the headlight 812 and the headlights 812 and 814 ofvehicle 830 are turned back on. Although in the present example only oneof the vehicles 810 and 830 turns its headlights off, in someimplementations both vehicles may turn their headlights off (or dimthem). Additionally or alternatively, in some implementations, any ofthe vehicles 810 and 830 may turn off (or dim) only some of the LEDs ineach headlight.

According to aspects of the disclosure, a blinking condition may occurwhen both vehicles 810 and 830 enter a cycle in which they see oncominglight sources and turn off (or just dim) their headlights, after whichboth vehicles realize that there is no light impinging on them anymoreand turn their headlight(s) back on. In some implementations, thevehicles 810 and 830 may prevent the blinking condition from occurringby exchanging communications for determining which one of them will turnits headlights off (or just dim them). For example, each of the vehicles810 and 830 may transmit to the other a message instructing to keep itsheadlights off (or dimmed) for a predetermined period of time (e.g., 30seconds). The message may be transmitted using the vehicle's headlights,a radio transceiver, and/or any other suitable type of device.

In some aspects, the vehicle 810 may use a segmented LED chip that ispart of the headlight 812 as a transceiver for exchanging communicationswith the vehicle 830 to determine which vehicle will turn its headlightsoff. Similarly, the vehicle 830 may use a segmented LED chip that ispart of the headlight 832 as a transceiver for exchanging communicationswith the vehicle 830 to determine which vehicle will turn its headlightsoff. The communications may be exchanged using any suitable type ofvisible light communication (VLC) protocol. Stated succinctly, accordingto the present example, any of the vehicles 810 and 830 may use asegmented LED chip that is part of its headlights to both illuminate theroad ahead of the vehicle and exchange communications with oncomingvehicles.

In some aspects, each of the vehicles 810 and 830 may include atransceiver that is separate from the vehicle's headlights, but stilluses a segmented LED chip, such as the segmented LED chip 100, totransmit communications in a visible or non-visible light band. Usingthe segmented LED chip in this manner may be advantageous as emitter anddetector LEDs in the segmented LED chip can be practically self-alignedas a result of the close spatial proximity between LEDs in the segmentedLED chip. They can be placed in a very tight beam, without the expenseof (periodic) alignment.

FIG. 10A is a diagram illustrating an example of another adaptive actionthat could be taken by the adaptive automotive lighting system of FIG. 8when oncoming traffic is encountered, according to aspects of thedisclosure. In this example, the headlight 812 of vehicle 810 uses atleast one segmented LED chip to illuminate the road ahead of vehicle810, such that different LEDs in the segmented LED chip are configuredto illuminate different portions of the space 822. The use of thesegmented LED chip permits vehicle 810 to turn down the brightness ofonly those LEDs that illuminate the spare occupied by vehicle 830 (e.g.,LEDs that might interfere with the vision of the driver of the vehicle830). As illustrated, vehicle 810 may turn down the brightness of theLEDs illuminating a portion 1010 of the space 822 to 30% percent of themaximum brightness which they are capable of providing. Similarly, thevehicle 810 may turn down the brightness of the LEDs illuminating aportion 1020 of the space 822 to 50% of their maximum brightness. At thesame time, the vehicle 810 may continue operating the remaining emitterLEDs in the headlight 814 at their full capacity, as shown. Furthermore,the vehicle 830 may completely turn off the LEDs in the headlight 832that illuminate a portion 1030 of the space 842.

Although in the example of FIG. 10A the LEDs in headlights 812 and 832are dimmed from side to side, in some implementations the LEDs in theheadlights 812 and 832 may be dimmed from top to bottom instead. Asillustrated in FIG. 10B, vehicle 810 may turn down the brightness of theLEDs in headlight 812 that illuminate a portion 1040 of the space 822 to30% percent of the maximum brightness which they are capable ofproviding. Similarly, the vehicle 810 may turn down the brightness ofthe LEDs m headlight 812 that illuminate a portion 1050 of the space 822to 50% of their maximum brightness. At the same time, the vehicle 810may continue operating the remaining emitter LEDs in the headlight 812at their full capacity, as shown. Furthermore, the vehicle 830 maycompletely turn off the LEDs in the headlight 832 that illuminate aportion 1060 of the space 842.

Additionally or alternatively, in some implementations, the headlightsof vehicles 810 and 820 may be dimmed both from left to right and top tobottom. As noted above, the spaces 822 and 842 are three-dimensional.Accordingly, the brightness of the LED(s) in headlight 812 thatilluminate any particular three-dimensional portion of the space 822 maybe independently changed. Similarly, the brightness of the LEDs inheadlight 832 that illuminate any particular three-dimensional portionof the space 842 may be independently changed, as well. As is furtherdiscussed below, this type of high granularity of adaptive lightingadjustment is made possible by the spatial proximity between emitter anddetector LEDs on the segmented LED chip, which permits them to bealigned with the same optical element.

FIG. 11A is an exploded view of an example of the headlight 812,according to aspects of the disclosure. The headlight 812 includes asegmented LED chip 1110 and an optical unit 1120. The segmented LED chip1110 includes a plurality of sections 1112, each of which includes atleast one LED that is configured to operate as an emitter, and at leastone other LED that is configured to operate as a detector. In someimplementations, any section of the segmented LED chip 1110 may includemultiple detector LEDs. Additionally, or alternatively any section ofthe LED chip 1110 may include detector LEDs that have differentrespective absorption bands. For example, one or more sections of thesegmented LED chip may include a first detector LED that is optimized todetect light emitted from halogen headlight, a second detector LED thatis optimized to detect light emitted from xenon headlights, and a thirdLED that is optimized to detect light from incandescent headlights.

Each of the sections 1112 is aligned with a different optical element1122 of the optical unit 1120. Each optical element 1122 may have adifferent central direction 1130, as shown in FIG. 11B. In someimplementations, the optical unit 1120 may include a lens array and eachof the optical elements 1122 may include a lens that is part of thearray. Additionally or alternatively, the optical unit may include aplurality of apertures (e.g., barrels or lens barrels). Each aperturemay be configured to guide light in a particular direction and/orreceive light that is arriving at the aperture from the particulardirection, while absorbing light that is incident on the aperture fromother directions. Stated succinctly, each optical element of the opticalunit 1220 may be any suitable type of device that is configure to guidelight to/from a particular direction.

As discussed above, during the operation of the headlight 812, lightfrom oncoming vehicle headlights is guided by the optical elements 1122to impinge on detector LEDs that are located in the same section 1112 asthe exact emitter LEDs that are illuminating the part of the road thatis occupied by the oncoming vehicle. The detector LEDs will absorbwavelengths of the oncoming light that have energy greater than thebandgap within the detector LEDs active regions. The absorbed light inthe detector LEDs will be converted into an electric current that passesto the electrical terminals of the detector LEDs. When biasedappropriately, the amount of current is related to the amount of lightthat is incident on the detector LEDs, which could be related to thedistance of the oncoming car. Thus, the emitter LEDs in a given sectionof the segmented LED chip 1110 may be dimmed in proportion to the amountlight sensed by the detector LEDs in that section. If a greater amountof light is detected, the LEDs may be dimmed to a lower brightness levelthan if a lesser amount of light were to be detected. In some aspects,the emitter LEDs may be gradually dimmed as the oncoming vehicle getscloser to the headlight 812.

As noted above, the detector LEDs that sense light emitted from theheadlights of oncoming vehicles are embedded in the same chip as theLEDs that emit light. As a result, the angles and/or regions that areilluminated by a given emitter LED can be made, by the optical unit1120, to be the same as the angles/regions that a given detector LEDlocated in the same section of the segmented LED chip 1110 is sensitiveto. More particularly, according to aspects of the disclosure, onlylight incident from certain angles and/or regions will be incident onany given section of the segmented LED chip 1110. For any given section1112 of the segmented LED chip 1110, light coming from the centraldirection 1130 of the given section's aligned optical element 1122 maybe predominantly passed through the given section's aligned opticalelement 1122 to reach the given section. Similarly light emitted byemitter LEDs in any given section 1112 of the segmented LED chip 1110may be guided by the given section's aligned optical element in theoptical element's central direction 1130.

As illustrated in FIG. 11B, an optical element 1122 a is configured toguide light emanating from section 1112 a of the segmented LED chip 1110in a central direction 1130 a. Similarly, the optical element 1122 a isconfigured to guide light that is incident on the optical element 1122 afrom the central direction 1130 a and (mostly) reflect and/or absorblight that is incident on the optical element 1122 a from otherdirections. Thus, as a result of being aligned with the optical element1122 a, the section 1112 a of the segmented LED clap 1110 is configuredto receive light that is predominantly coming from the central direction1130. Similarly, as a result of being aligned with the optical element1122 a, the section 1112 a of the segmented LED chip 1110 is configuredto emit light predominantly in the central direction 1130.

Furthermore, as illustrated in FIG. 11B, an optical element 1122 b isconfigured to guide light emanating from section 1112 b of the segmentedLED chip 1110 in a central direction 1130 b. Similarly, the opticalelement 1122 b is configured to guide light that is incident on theoptical element 1122 b from the central direction 1130 b and (mostly)reflect and/or absorb light that is incident on the optical element 1122b from other directions. Thus, as a result of being aligned with theoptical element 1122 b, the section 1112 b of the segmented LED chip1110 is configured to receive light that is predominantly coming fromthe central direction 1130 b. Similarly, as a result of being alignedwith the optical element 1122 b, the section 1112 b of the segmented LEDchip 1110 is configured to emit light predominantly in the centraldirection 1130 b.

Furthermore, as illustrated in FIG. 11B, an optical element 1122 c isconfigured to guide light emanating from section 1112 c of the segmentedLED chip 1110 in a central direction 1130 c. Similarly, the opticalelement 1122 c is configured to guide light that is incident on theoptical element 1122 c from the central direction 1130 c and (mostly)reflect and/or absorb light that is incident on the optical element 1122c from other directions. Thus, as a result of being aligned with theoptical element 1122 c, the section 1112 c of the segmented LED chip1110 is configured to receive light that is predominantly coming fromthe central direction 1130 c. Similarly, as a result of being alignedwith the optical element 1122 b, the section 1112 c of the segmented LEDchip 1110 is configured to emit light predominantly in the centraldirection 1130 c.

Stated succinctly, each of the optical elements 1122 may have adifferent central direction 1130, and each section 1112 of the segmentedLED chip 1110 may be aligned with a different optical element 1122. As aresult, each section of the segmented LED chip 1110 may be associatedwith a different portion of the space illuminated by the segmented LEDchip 1110.

FIG. 12 is a schematic diagram illustrating the way light emitted fromdifferent sections of the segmented LED chip 1110 is guided by theoptical unit 1120, according to aspects of the disclosure. Asillustrated, the optical element 1122 a causes light emitted fromsection 1112 a to be directed to portion 1210 a of the space 822.Similarly, the optical element 1122 a causes light coming from theportion 1210 a to be directed to the section 1112 a. The optical element1122 b causes light emitted from section 1112 b to be directed toportion 1210 b of the space 822. Similarly, the optical element 1122 bcauses light coming from the portion 1210 b to be directed to thesection 1112 b. The optical element 1122 c causes light emitted fromsection 1112 c to be directed to portion 1210 c of the space 822.Similarly, the optical element 1122 c causes light coming from theportion 1210 c to be directed to the section 1112 c. The optical element1122 d causes light emitted from section 1112 d to be directed toportion 1210 d of the space 822. Similarly, the optical element 1122 dcauses light coming from the portion 1210 d to be directed to thesection 1112 d. The optical element 1122 e causes light emitted frontsection 1112 e to be directed to portion 1210 e of the space 822.Similarly, the optical element 1122 e causes light coming from theportion 1210 e to be directed to the section 1112 e. The optical element1122 f causes light emitted from section 1112 f to be directed toportion 1210 f of the space 822. Similarly, the optical element 1122 fcauses light coining from the portion 1210 f to be directed to thesection 1121 f. The optical element 1122 g causes light emitted fromsection 1112 g to be directed to portion 1210 g of the space 822.Similarly, the optical element 1122 g causes light coming from theportion 1210 g to be directed to the section 1112 g. The optical element1122 h causes light emitted from section 1112 h to be directed toportion 1210 h of the space 822. Similarly, the optical element 1122 hcauses light coming from the portion 1210 h to be directed to thesection 1112 h. The optical element 1122 i causes light emitted fromsection 1112 i to be directed to portion 1210 i of the space 822.Similarly, the optical element 1122 i causes light coming from theportion 1210 i to be directed to the section 1112 i.

According to aspects of the disclosure, the emitter LEDs in any sectionof the segmented LED chip 1110 may be controlled only (or mostly) basedon signals generated by detector LEDs in that section. This in turn mayresult in the brightness of the LEDs in any given section of thesegmented LED chip 1110 being controlled based on the lightingconditions in the specific area (or space) illuminated by them. Asdiscussed with respect to FIG. 10, this type of granular control overdifferent portions of the segmented LED chip 1110 permits the adjustmentof only those LEDs in the headlight 812 that impinge on oncomingtraffic.

Although in the present example, the headlight 812 includes a singlesegmented LED chip, alternative implementations are possible in whichmultiple segmented LED chips are used. In such instances, each segmentedLED chip may be aligned with a different optical element 1122 of theoptical unit 1120. Furthermore, although in the present example theoptical unit 1120 includes nine optical elements, alternativeimplementations are possible in which a different number of opticalunits is included in the optical unit (e.g., 2 optical units, 4 opticalunits, 5 optical units, etc.) Furthermore, the headlight 812 may includeany suitable type of controller for driving the segmented LED chip 1110or multiple LED chips that are part of the headlight 812. For example,the headlight 812 may include a controller such as the controller 620 orthe controller 720.

According to aspects of the disclosure, the detector LEDs in thesegmented LED chip 1110 may be susceptible to crosstalk. Crosstalk canoccur when light emitted from the segmented LED chip 1110 is reflectedby the optical unit 1120 (or another element of the headlight 812) hackto the detector LEDs in the segmented LED chip 1110. The occurrence ofcrosstalk can compromise the sensitivity of the detector LEDs.Accordingly, to improve the detector LED's sensitivity to the incominglight, emitter LED(s) may e cyclically dimmed or shut off for a shortperiod in which detector LED(s) are read. The period for which theemitter LEDs are dimmed or shut off can be shorter than thetime-response of the human eye, making the dimming (or shutting off)imperceptible.

FIG. 13 is flowchart of an example of a process 1300 for avoidingcrosstalk between emitter LEDs and reflector LEDs in the segmented LEDchip 1110, according to aspects of the disclosure. As illustrated,according to the process 1300, an emitter LED in the segmented LED chip1110 is cycled between a first state (step 1310) and a second state(step 1320), while readings are taken from one or more designateddetector LEDs that are located in the same section (or group) of thesegmented LED chip 1110 only when the emitter LED is in the second state(step 1330).

In some implementations, the designated detector LEDs can becontinuously operated as such. Additionally or alternatively, in someimplementations, the one or more designated detector LEDs can beoperated as emitters when the emitter LED is in the first state, andswitched to detector mode, by changing the polarity of their respectivebiases, during periods in which the emitter LED is in the second state.

In some implementations, the second state of the emitter LED maycoincide with the off-periods of a PWM wave used to drive the emitterLED. Additionally or alternatively, the second state may coincide withboth on-periods and off-periods of the PWM wave. For example, theemitter LED may be in the first state when the PWM wave that drives theemitter LED has a first duty cycle. Furthermore, the emitter LED may bein the second state when the PWM wave that drives the emitter LED has asecond duty cycle that is shorter than the first duty cycle. Statedsuccinctly, in some implementations, the emitter LED may be transitionedbetween the first state and the second state by varying the duty cycleof the PWM wave (and/or amount of current) that drives it. According toaspects of the disclosure, the first state of the emitter LED may be onein which the emitter LED is operating at a first brightness level (e.g.,100% of the emitters' maximum brightness, 80% of the emitters' maximumbrightness, etc.) The second state of the emitter LED may be one inwhich the emitter LEDs are operating at a second brightness level thatis lower than the first brightness level. For example, the second statemay be one in which the emitter LED is switched off completely or astate in which the emitter LED is dimmed (e.g., operating at 40% of itsmaximum brightness). In some aspects, all emitters LEDs in the segmentedLED chip 1110 (or another type of LED matrix) may be synchronouslycycled between first and second states, as discussed, but the respectivefirst states and/or the respective second states for emitter LEDslocated in different sections (or groups) of the segmented LED chip 1110may differ. For example, the emitter LEDs in one group (and/or chipsection) may cycle between 80% and 40% brightness, while the emitterLEDs in another group (and/or chip section) may cycle between 70% and40% brightness.

According to aspects of the disclosure, another type of crosstalk mayoccur when light emitted by one or more emitter LEDs in the segmentedLED chip 1110 is directed towards neighboring LEDs. FIGS. 14A and 14Billustrate an example of a segmented LED chip 1400 that is optimized toavoid such crosstalk. More particularly, FIG. 14A is a top-down view ofthe segmented LED chip 1400, while FIG. 14B is a side view of thesegmented LED chip 1400. The segmented LED chip 1400 includes aplurality of LEDs 1410 that are separated by trenches 1420. Inside thetrenches 1420, a fence structure is formed that includes a plurality ofcells. Inside each cell, a different LED 1410 is disposed, as shown. Thewalls of each cell may be taller than the LED that is enclosed in it,thus preventing light emitted by that LED from travelling sidewaystowards neighboring LEDs. In some aspects, the fence structure 1430 maybe formed of any suitable material (e.g., glass, metal, etc.) withreflective coating, such as a metal (e.g., silver), dielectricdistributed Bragg reflectors (DBRs) or silicone-based optical scatteringmatrix, for example. In some aspects, the fence structure 1430 may beformed by a combination of materials, such as a dielectric fence coatedwith a reflective metal, for example. In some implementations, the wallsof each cell of the fence structure 1430 may be between 100% and 1000%of the height of the LED that is enclosed in it. The elements of thefence structure 1430 may be formed using any suitable type of process,such as plasma enhanced chemical vapor deposition, atomic layerdeposition, evaporation deposition, sputtering deposition or siliconemolding, for example.

FIG. 15 is a flowchart of an example of a process 1500 for operating anLED matrix, according to aspects of the disclosure. The LED matrix mayconsist of a single segmented LED, or include multiple segmented LEDchips, and/or include one or more non-segmented LED chips. The process1500 may be performed by any suitable type of controller that isoperatively coupled to the LED matrix.

At step 1510, a plurality of LEDs in the matrix is arranged into groups.In some implementations, arranging the LEDs into groups may includeconnecting each of the LEDs to one of a plurality of driver circuits.(E.g., see FIG. 6). Additionally or alternatively, arranging the LEDsinto groups may include generating and storing in a memory a datastructure identifying the groups. For example, the data structure maymap an identifier of each group (e.g., E.g., “Group 1”, “Group 2”, etc.)to a list a of identifiers (e.g., addresses) of LEDs that are part ofthe group.

For instance, the data structure may be a table, as illustrated by Table1, below:

TABLE 1 Data Structure Identifying a Plurality of LED Groups Group IDLEDs in Group Group 1 (1, 1), (1, 2) (1, 3), (2, 1) Group 2 (2, 2), (2,3), (3, 1) Group 3 (3,2), (3,3)

In the example of Table 1, each LED is identified by a double (X,Y) inwhich X is a column number and Y is a row number of the location of theLED in an LED matrix. Although in the present example, X-Y coordinate isused to address the LEDs in the LED matrix, alternative implementationsare possible in which any suitable type of alphanumeric identifier thatcorresponds to the LEDs' respective locations can be used instead. Asdiscussed further below, in some implementations, the addresses may beused to identify LEDs in the matrix that are collocated.

At step 1520, the LEDs in each group are configured. According toaspects of the disclosure, configuring the LEDs in a given group mayinclude applying one of a forward bias or a reverse bias to each of theLEDs the given group, effectively causing each of the LEDs to operate aseither an emitter LED or a detector LED. In some implementations, themagnitude of the bias applied to emitter and detector LEDs may be thesame, and only the polarity may vary. Additionally or alternatively, insome implementations, the bias applied to detector LEDs may differ inboth magnitude and polarity from the bias of the emitter LEDs.Additionally or alternatively, the magnitude of the bias applied todifferent emitter LEDs in a given group may be different. Additionallyor alternatively, the magnitude of the bias applied to different emitterLEDs in a given group may be same. Additionally or alternatively, themagnitude of the bias applied to different detector LEDs in a givengroup may be different. Additionally or alternatively, the magnitude thebias applied to different detector LEDs in a given group may be same.

Additionally or alternatively, configuring the LEDs in a given group mayinclude identifying one or more LEDs in the group that are optimized tooperate as detectors and applying a reverse bias to them. (E.g., seeFIGS. 4 and 5.) In some implementations, the optimized LEDs may beidentified based on a data structure stored the memory of the controllerthat identities LEDs in the group that are optimized as receivers. Insome implementations, the data structure may also identify a biasmagnitude for each optimized LEDs as differently-doped LEDs may requiredifferent bias. In some implementations, each of the optimized LEDs maybe biased in accordance with a corresponding bias magnitude that isspecified in the data structure.

Additionally or alternatively, in some implementations, configuring theLEDs in a given group may include retrieving a data structureidentifying a particular operational pattern and imparting thatoperational pattern on the given group by biasing the LEDs in the givengroup accordingly. In some aspects, the data structure may include adifferent identifier for each LED in the group that specifies thepolarity of the bias to be applied to that LED. For example, the datastructure may be a table, as shown below:

TABLE 2 A Data Structure Representing an Operational Pattern for a 3 × 3LED matrix. 0 0 0 0 1 0 0 0 0

According to the example of Table 2, the data structure may be a 3×3matrix containing binary values, where 0 indicates that a forward biasis to be applied to a given LED, and “1” indicates that a reverse biasis to be applied. The data structure may be applied to any group of LEDsin which the LEDs are arranged in a 3×3 matrix, such that any valuei_(row, column) in the data structure specifies the bias ofLED_(row, column). In the present example, the value of i_(2,2) in thedata structure equals 1, which indicates that the LED is in row 2,column 2 is to be put m a reverse bias. Similarly, the value of i_(1,1)in the data structure equals 0, which indicates that the LED located inrow 1, column 1 is to be put in a forward bias. Although in the presentexample, the data structure identify only bias polarity, furtherimplementations are possible in which the data structure identifies arespective bias magnitude for each LED in a matrix, or both.

At step 1530 each of the groups is operated to provide adaptive lightingto the area illuminated by that group. In some implementations, each ofthe group may be operated autonomously from the rest. Additionally oralternatively, in some implementations, each group may be operated inaccordance with the process 1600, which is discussed with respect toFIG. 16 below.

At step 1540, a detection is performed of whether a regrouping event isgenerated. In some implementations, the regrouping event may begenerated as a result of a user input. If a regrouping event isdetected, the process 1500 returns to step 1510 and the LEDs areregrouped. According to aspects of the disclosure, regrouping the LEDsmay include one or more of: (i) consolidating all LEDs into a singlegroup, consolidating at least two existing groups into one, and/ordividing at least one existing group into multiple groups. In thisregard, alternative implementations are possible in which all LEDs inthe LED matrix are assigned to the same group. Furthermore, alternativeimplementations are possible, in which each of the groups consists ofall LEDs found in a different segmented LED chip.

FIG. 16 is a flowchart of an example of a process 1600 for operating agiven group of LEDs, as discussed with respect to step 1530 of theprocess 1500, according to aspects of the disclosure. At step 1610, afirst signal is generated at least in part by one or more detector LEDsin the given group. At step 1620, the brightness of the emitter LEDs inthe group is changed based on the first signal. At step 1630, a secondsignal that is generated at least in part by one or more emitter LEDs inthe given group is detected. At step 1640, the operational mode of atleast one of the LEDs in the group is changed based on the secondsignal.

According to aspects of the disclosure, changing the operational mode ofa given LED may include changing the bias of that LED from reverse toforward or from forward to reverse. For example, if a reverse bias isapplied to an emitter LED, that LED may begin operating as a detectorLED as a result. As another example, if a forward bias is applied to adetector LED, that LED may begin operating as an emitter LED.

In some implementations, step 1640 may be performed in response to thesecond signal having a characteristic that meets a predeterminedthreshold. For example, if the dynamic range of the second signal fallsbelow a threshold, the bias of one or more emitter LEDs can be changedto increase the number of detector LEDs in the group and attain greatersensitivity. As another example, if the second signal indicates that thearea at which the group of LEDs is directed is not illuminatedsufficiently, the bias of a detector LED can be changed to add an extraemitter LED to the group.

In some implementations, the one or more detector LEDs in the group maybe continuously operated as such. Alternatively, in someimplementations, the one or more detector LEDs may be periodicallyswitched from forward to reverse bias to take a reading, and thenreturned to forward bias. The switching of the bias polarity may occurvery rapidly (e.g., <10 ns) to allow for light collection. In someimplementations, the polarity of the bias of the one or more detectorLEDs in the given group may be switched at a high frequency, so that theswitching can be imperceptible to the human eye.

FIG. 17 is a flowchart of an example of a process 1700 for operating anLED matrix, according to aspects of the disclosure. The LED matrix mayconsist of a single segmented LED, or include multiple segmented LEDchips, and/or include one or more non-segmented LED chips. The process1700 may be performed by any suitable type of controller that isoperatively coupled to the LED matrix.

At step 1710, at least some of the LEDs in a plurality are configured tooperate as emitter LEDs by applying forward bias to them. At step 1720,the remaining ones of the plurality of LEDs are configured to operate asdetector LEDs by applying a reverse bias to them.

At step 1730, the brightness of a given emitter LED in the matrix ischanged based on a signal that is generated by one or more detector LEDsthat are collocated with the given emitter LED. According to aspects ofthe disclosure, two LEDs may be collocated when they are in the samesection of the LED matrix, such as a top-right quarter, top leftquarter, bottom-right quarter, or a bottom-left quarter, etc.

Additionally or alternatively, two LEDs may be collocated when they arewithin predetermined distance from one another in the LED matrix. Insome implementations, the distance between a first LED and a second LEDmay equal the count of other LEDs that are situated along a straightline connecting the first LED and the second LED. For instance, if thefirst LED and the second LED are located next to each other, thedistance may be zero. As another example, if there is one other LEDbetween the first LED and the second LED, the distance between them maybe 1. In some implementations, the distance between two LEDs may bedetermined based on the addresses of those LEDs.

Additionally or alternatively, in some implementations, two LEDs may becollocated if they are aligned with the same optical element. (E.g., seeFIGS. 11A-B). Additionally or alternatively, in some implementations,two LEDs may be collocated if they are part of the same LED group. Insome aspects, whether two LEDs are collocated may be determined based ona data structure stored in a memory of the controller of the LED matrix.The data structure may include a plurality of lists, wherein each listincludes identifiers of the LEDs in a particular group. Additionally oralternatively, the data structure may include a plurality of lists,wherein each list includes identifiers of the LEDs that are aligned witha particular optical element in a larger optical unit. (E.g., see FIGS.11A-B showing optical elements 1122 in the optical unit 1120.)

Although some of the concepts disclosed herein are presented in thecontext of adaptive automotive lighting, it will be understood that thedisclosed segmented LED chip implementations, adaptive lighting systemimplementations, and processes for operating adaptive lighting systemscan be employed in any context. For example, they can be used in indoorlighting systems, street lighting systems, stage lighting systems,decorative lighting systems, and greenhouse lighting systems. Thus, thedisclosure is not limited to the examples presented herein.

FIGS. 1-17 are provided as an example only. At least some of theelements discussed with respect to these figures can be arranged indifferent order, combined, and/or altogether omitted. It will beunderstood that the provision of the examples described herein, as wellas clauses phrased as “such as,” “e.g.”, “including”, “in some aspects,”“in some implementations,” and the like should not be interpreted aslimiting the disclosed subject matter to the specific examples.

Having described the invention in detail, those skilled in the art willappreciate that, given the present disclosure, modifications may be madeto the invention without departing from the spirit of the inventiveconcepts described herein. Therefore, it is not intended that the scopeof the invention be limited to the specific embodiments illustrated anddescribed.

What is being claimed is:
 1. A method for communicating betweenautomotive vehicles, the method comprising: illuminating, with aheadlight including an array of light-emitting diodes (LEDs), a portionof a road ahead of a vehicle; and exchanging, with the headlight,communications with an oncoming vehicle via light transmission anddetection through the headlight, the exchanged communications includinga determination of which of the vehicle or the oncoming vehicle is toperform a function including at least one function selected from a groupof functions that include: switching off at least one headlight of thevehicle or the oncoming vehicle and dimming the at least one headlightof the vehicle or the oncoming vehicle.
 2. The method of claim 1,wherein the exchanged communications include instructions to perform thefunction for a predetermined period of time.
 3. The method of claim 1,wherein the exchanged communications are exchanged using modulatedvisible light.
 4. The method of claim 1, further comprising controllingactivation of power to the array of light-emitting diodes with acontroller.
 5. The method of claim 4, further comprising transmittingand receiving the exchanged communications via a transceiver separatefrom the headlight and coupled to the controller.
 6. The method of claim5, wherein the transceiver transmits and receives the communications ina visible portion of the electromagnetic spectrum via the array oflight-emitting diodes.
 7. The method of claim 6, wherein the visibleportion of the electromagnetic spectrum is used to illuminate theportion of the road.
 8. The method of claim 4, wherein the controller:applies a forward bias to a first LED in the array of LEDs such that thefirst LED functions as an emitter to provide the exchangedcommunications; and applies a reverse bias to a second LED in the arrayof LEDs such that the second LED functions as a detector to receive theexchanged communications.
 9. The method of claim 4, wherein the array ofLEDs is disposed on a segmented LED chip, the segmented LED chipincluding a plurality of LEDs, the LEDs in the plurality of LEDs beingseparated by trenches formed on the segmented LED chip, the LEDs in theplurality being arranged in a plurality of sections, each sectionincluding at least one LED configured to function as an emitter and atleast one LED configured to function as a detector.
 10. The method ofclaim 9, wherein: the exchanged communication indicates to change abrightness; and the controller changes a brightness of at least oneemitter in a specified section based on the exchanged communication fromthe oncoming vehicle being detected by at least one detector in thespecified section.
 11. The method of claim 9, wherein the plurality ofsections includes a first section and a second section, such that lightfrom the LEDs in the first section illuminates a first volume above theroad ahead of the vehicle, and light from the LEDs in the second sectionilluminates a second volume above the road ahead of the vehicle, thefirst volume and the second volume being at least partiallynon-overlapping.
 12. The method of claim 11, wherein the first volume ispositioned substantially horizontally adjacent to the second volume. 13.The method of claim 11, wherein the first volume is positionedsubstantially vertically adjacent to the second volume.
 14. The methodof claim 11, wherein the group of functions further includes: switchingoff the LEDs in the first section but not the second section and dimmingthe LEDs in the first section but not the second section.
 15. A methodfor communicating between automotive vehicles, the method comprising:illuminating a portion of a road ahead of a vehicle with a segmentedlight-emitting diode (LED) chip in a headlight, the segmented LED chipincluding a plurality of LEDs, the LEDs in the plurality being arrangedin a plurality of sections, each section including at least one firstLED and at least one second LED; and exchanging communications with anoncoming vehicle via light transmission from at least one of the firstLEDs and light detection through at least one of the second LEDs, theexchanged communications including a determination of which of thevehicle or the oncoming vehicle is to perform a function including atleast one function selected from a group of functions that include:switching off at least one headlight of the vehicle or the oncomingvehicle and dimming the at least one headlight of the vehicle or theoncoming vehicle.
 16. The method of claim 15, further comprising:applying, with a controller, a forward bias to each of the first LEDssuch that the first LEDs function as emitters to provide the exchangedcommunications; applying, with the controller, a reverse bias to each ofthe second LEDs such that the second LEDs function as detectors toreceive the exchanged communications.
 17. The method of claim 15,wherein the plurality of sections includes a first section and a secondsection, such that light from the LEDs in the first section illuminatesa first volume above the road ahead of the vehicle, and light from theLEDs in the second section illuminates a second volume above the roadahead of the vehicle, the first volume and the second volume being atleast partially non-overlapping.
 18. The method of claim 17, wherein thefirst volume is positioned substantially horizontally adjacent to thesecond volume.
 19. The method of claim 17, wherein the first volume ispositioned substantially vertically adjacent to the second volume.
 20. Amethod for communicating between automotive vehicles, the methodcomprising: illuminating, with a headlight, a portion of a road ahead ofa vehicle having an automotive communication system; exchangingcommunications with an oncoming vehicle via light transmission anddetection through the headlight, determining, via the exchangedcommunications, which vehicle is to perform a function including atleast one function selected from: switching off its headlights anddimming its headlights, the headlight including a segmented LED chipincluding a plurality of LEDs that are separated by trenches formed onthe segmented LED chip, the LEDs in the plurality being arranged in aplurality of sections, each section including at least one first LED andat least one second LED configured to function as a detector; applying aforward bias to the first LEDs such that the first LEDs function asemitters to provide the exchanged communications; and applying a reversebias to the second LEDs such that the second LEDs function as detectorsto receive the exchanged communications.